Hello Sultan! “Sluggish” and “lazy” are similar but they are not exactly the same. They are both adjectives that can be used to describe a person who is inactive, but often for different reasons. Sluggish usually describes a lack of energy. If you are feeling tired and sick, you probably feel sluggish - you don’t have energy to be active or do work. Let’s say you are feeling very sick and you have low energy, but you still want to work. In this case, you might be sluggish, but not lazy. Lazy usually describes someone who doesn’t WANT to be active or do work. The person is CHOOSING to be inactive. So, maybe you have a lot of energy but you do not want to work. Someone could say you are lazy, but not sluggish. Does this answer your question? Let me know if you would like me to make it more clear :)

More like "lethargic"

Thank you both of you for your efforts

Quite right Ueda. Nick completely ignored the fact that 'sluggish' can also be used for objects. Another example is a slow-flowing river.

I am not a native speaker of English either. So, I am not sure if what I wrote above is correct.